一个类似于windows标准计算器的程序 用Java语言编写 可以进行简单的加减乘除 取余 ，平方求导数 ，存储数字 ，调用数字等功能-A similar standard windows calculator program written in Java can be used to check simple addition and subtraction, multiplication and division, the square of the number of derivation, storage figures, the number of features such as call